docs: def from_named_function(cls, function):
          """Make a :class:`SassFunction` object from the named ``function``.
          Function name and arguments are automatically inspected.
  
          :param function: the named function to be called
          :type function: :class:`types.FunctionType`
          :returns: a custom function wrapper of the ``function``
          :rtype: :class:`SassFunction`
  
          """
          if not getattr(function, '__name__', ''):
              raise TypeError('function must be named')
          return cls.from_lambda(function.__name__, function)